What Is the Characteristic Equation of the Differential Equation $\frac{d^{2} y}{d x^{2}}+5 \frac{d y}{d x}-6 y=0$

Multiple Choice

What is the characteristic equation of the differential equation $\frac{d^{2} y}{d x^{2}}+5 \frac{d y}{d x}-6 y=0$ ?

A) $(r+5) (r-6) =0$
B) $(r+5) (r-1) =0$
C) $r^{2}-5 r+6=0$
D) $r^{2}+5 r-6=0$